Banking giant Maybank and other companies in Malaysia are looking into investment opportunities in the southern Philippines, as Manila puts the finishing touches on a deal to end one of Asia's longest and deadliest insurgencies.

Maybank, Malaysia's biggest bank, has announced that it is investing US$300 million to open new branches across the Philippines, including in Mindanao, the country's biggest and southernmost island that has been wracked by a decades-old war waged by Muslim secessionists.

Jane Francisco, a member of Philippine President Benigno Aquino's business delegation during his two-day state visit to Kuala Lumpur last week, told The Straits Times yesterday that Azmil Khalid, head of the Malaysia-Philippines Business Council, is "very bullish" and believes Mindanao "is the way to go".

Malaysia's International Trade and Industry Minister Mustapa Mohamed told reporters in Kuala Lumpur: "The (Philippines) has massive potential amid political and economic stability."

Bilateral trade between the Philippines and Malaysia stood at $4.5 billion last year, compared with $16.5 billion total trade with the Philippines' biggest trading partner, Japan.

International monitors observing peace talks between Manila and the Muslim rebels said at least two Malaysian companies had already made inquiries on investing in palm oil, banana and other agricultural products in Mindanao.

"There is tremendous opportunity for that to come up," Alistair MacDonald, head of the observers' team, said at a news conference. But he emphasised that "the risk factor has to be seen as normal". "The conditions have to be laid down for investors to cross the line between expressing interest and actually investing," he said.

Hard-line guerillas are threatening to derail a peace deal signed last month outlining a power-sharing agreement between the Philippine government and the 12,000-strong Moro Islamic Liberation Front (MILF) over Muslim-held areas in Mindanao. The Bangsamoro Islamic Freedom Fighters, a splinter group of the MILF, has continued to attack government forces while courting Muslim rebels disgruntled with the peace deal.

Followers of Nur Misuari - founder of MILF's rival guerilla faction, the Moro National Liberation Front - attacked the southern port of Zamboanga in September last year in an effort to wreck the talks, leaving more than 220 people dead.

Wrapping up his two-day state visit to Malaysia, Aquino urged some 200 of Malaysia's top businessmen on Friday to invest in Mindanao, saying the island is "so fertile that a patch of it left unattended for a short while becomes quickly overgrown".

"Now that lasting peace in that particular region has come within reach, perhaps investing this early in Mindanao is an opportunity that is presenting itself to all of us," he said.

He said his administration was set on transforming Mindanao into the Philippines' palm oil capital, to benefit the island's 4.4 million-strong Muslim population.